How long is the flight from Seattle to Washington, D.C. Dulles Intl Airport?

United Airlines and Alaska Airlines can get you from Seattle to Washington, D.C. Dulles Intl Airport in just under 5h 03m. Your travel time can differ by up to 2h 58m. Seattle and Washington, D.C. Dulles Intl Airport are separated by a distance of 3700 km. This flight may include one or multiple stops.

Weekly flight availability from Seattle to Washington, D.C. Dulles Intl Airport

The most flights from SEA to IAD are scheduled on a Tuesday (20 on average). You will have fewer flight options on Sunday, which is when the least amount of flights are scheduled (8 on average).

In terms of precipitation, rainfall in Washington, D.C. Dulles Intl Airport ranges from 66.0 - 102.0 mm per month. May is typically the wettest month, when rainfall can reach 102.0 mm. February is typically the driest time to visit Washington, D.C. Dulles Intl Airport when rainfall is around 66.0 mm.

If weather is an important factor for your trip to Washington, D.C. Dulles Intl Airport, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 27.0 C. Travellers hoping to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 2.0 C).

What are the cheapest flights from Seattle to Washington, D.C. Dulles Intl Airport?

While on average a flight from Seattle to Washington, D.C. Dulles Intl Airport is generally C$ 1,103, our data shows the cheapest flight currently is C$ 318. When looking at the most popular route, (Seattle/Tacoma Intl - Washington, D.C. Dulles Intl), you can expect to pay C$ 465 for that flight.

What are the most reliable airlines from Seattle to Washington, D.C. Dulles Intl Airport?

Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Seattle to Washington, D.C. Dulles Intl Airport on time: Qatar Airways (93%), Iberia (91%), Austrian Airlines (90%).

What airport do you fly from for flights from Seattle to Washington, D.C. Dulles Intl?

If you book a flight to Washington, D.C. Dulles Intl from Seattle, you will be flying from Seattle/Tacoma Intl, which is the city’s only airport. Seattle/Tacoma Intl (SEA) is located 18.4 km from the centre of Seattle. There are 11 flights from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl per day from 0 different airlines.

Can I find deals for flights from Seattle to Dulles Intl that include hotel bookings?

Yes. In addition to deals on Seattle to Dulles Intl flights, Cheapflights offers vacation packages that include both flights and hotel.

How can I find direct flights from Seattle to Dulles Intl?

After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Seattle to Dulles Intl.

Can I find deals for business class flights from Seattle to Dulles Intl?

Yes. Cheapflights offers flight deals from Seattle to Dulles Intl by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

C$ 261+ Cheap Flights from Seattle to Washington, D.C. Dulles Intl Airport

Cheapflights Tip: The best prices from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl are usually found in February or April, booked 77 days in advance, depart on a Wednesday or Tuesday and return on a Monday

Cheap flight deals from Seattle to Dulles Intl

Enter your travel dates to find the best prices.

Cheapest

Best

Direct

Last-minute

One-way

Cheapest flights from Seattle to Dulles Intl
Explore the most affordable flight options available from Seattle to Dulles Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 9 September 2026.

Thu 8/1011:14 p.m. -

Nonstop5h 03m

Sat 10/105:45 p.m. -

Nonstop5h 52m

Deal found 6/9C$ 422

Sun 25/1011:10 p.m. -

1 stop8h 02m

Wed 28/107:05 a.m. -

Nonstop5h 51m

Deal found 4/9C$ 423

Wed 7/1011:14 p.m. -

Nonstop5h 03m

Sat 10/101:05 p.m. -

Nonstop5h 46m

Deal found 6/9C$ 425

Tue 13/103:56 p.m. -

Nonstop5h 03m

Tue 20/107:24 p.m. -

1 stop17h 04m

Deal found 7/9C$ 426

Sun 25/108:09 a.m. -

Nonstop4h 59m

Tue 3/115:50 p.m. -

Nonstop6h 06m

Deal found 7/9C$ 429

Wed 4/117:00 a.m. -

1 stop7h 24m

Sun 8/116:10 a.m. -

1 stop9h 09m

Deal found 4/9C$ 432

Tue 13/103:56 p.m. -

Nonstop5h 03m

Wed 21/107:24 p.m. -

1 stop17h 04m

Deal found 7/9C$ 433

Sun 25/1011:10 p.m. -

1 stop8h 02m

Mon 26/106:59 p.m. -

1 stop8h 00m

Deal found 7/9C$ 437

Sat 10/103:56 p.m. -

Nonstop5h 03m

Tue 13/107:24 p.m. -

1 stop21h 53m

Deal found 7/9C$ 441

Fri 23/101:56 p.m. -

1 stop8h 01m

Mon 26/105:50 p.m. -

Nonstop6h 06m

Deal found 5/9C$ 445

Fri 2/101:56 p.m. -

1 stop8h 02m

Sun 4/106:10 a.m. -

1 stop8h 17m

Deal found 7/9C$ 447

Find flight deals from Seattle to Dulles Intl

Round-trip from	C$ 422
One-way from	C$ 261
Popular in	January
Cheapest in	February
Average price	C$ 520
Good round-trip deal	C$ 393 or less
Good one-way deal	C$ 736 or less

United Airlines
8/10-10/10
Nonstop
10h 55m total
Seattle to Washington, D.C.

Search Deals

United Airlines
15/10-31/12
Nonstop
5h 03m total
Seattle to Washington, D.C.

Search Deals

Highest demand for flights based on searches. 7% potential increase in price (C$ 69 potential increase over avg. RT price).

Search Deals

Cheapest flight prices on average. 4% potential price decrease (C$ 39 potential savings vs. average RT price).

Search Deals

Average for round-trip flights in September 2026

Search Deals

Price to beat on a round-trip flight from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl.

Search Deals

Price to beat on a one-way flight from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl.

Search Deals

Cheapflights Fare Finder

Use the filters below to find and compare flights from Seattle to Washington, D.C. Dulles Intl Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

SeattleWashington, D.C.

SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl

SEAIAD

Seattle/Tacoma Intl

Tue 1/12

3:59 p.m.-11:59 p.m.

Nonstop5h 00m

Washington, D.C. Dulles Intl

Wed 31/12

12:00 a.m.-9:00 p.m.

Nonstop0h 00m

C$ 274

SeattleWashington, D.C.

SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl

SEAIAD

Seattle/Tacoma Intl

Sat 3/10

8:25 a.m.-4:31 p.m.

Nonstop5h 06m

Washington, D.C. Dulles Intl

Wed 31/12

12:00 a.m.-9:00 p.m.

Nonstop0h 00m

C$ 280

SeattleWashington, D.C.

SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl

SEAIAD

Seattle/Tacoma Intl

Sun 11/10

9:36 p.m.-5:40 a.m.

Nonstop5h 04m

Washington, D.C. Dulles Intl

Wed 31/12

12:00 a.m.-9:00 p.m.

Nonstop0h 00m

C$ 288

Quickest round-trip

SeattleWashington, D.C.

SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl

SEAIAD

Seattle/Tacoma Intl

Sun 25/10

8:09 a.m.-4:08 p.m.

Nonstop4h 59m

Washington, D.C. Dulles Intl

Wed 31/12

12:00 a.m.-9:00 p.m.

Nonstop0h 00m

C$ 302

SeattleWashington, D.C.

SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl

SEAIAD

Seattle/Tacoma Intl

Mon 2/11

12:20 p.m.-5:19 a.m.

2 stops13h 59m

Washington, D.C. Dulles Intl

Wed 31/12

12:00 a.m.-9:00 p.m.

Nonstop0h 00m

C$ 302

SeattleWashington, D.C.

SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl

SEAIAD

Seattle/Tacoma Intl

Wed 3/3

3:51 p.m.-7:35 a.m.

2 stops12h 44m

Washington, D.C. Dulles Intl

Wed 31/12

12:00 a.m.-9:00 p.m.

Nonstop0h 00m

C$ 302

SeattleWashington, D.C.

SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl

SEAIAD

Seattle/Tacoma Intl

Sun 4/10

9:36 p.m.-5:40 a.m.

Nonstop5h 04m

Washington, D.C. Dulles Intl

Wed 31/12

12:00 a.m.-9:00 p.m.

Nonstop0h 00m

C$ 343

SeattleWashington, D.C.

SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl

SEAIAD

Seattle/Tacoma Intl

Sun 7/3

8:25 a.m.-4:26 p.m.

Nonstop5h 01m

Washington, D.C. Dulles Intl

Wed 31/12

12:00 a.m.-9:00 p.m.

Nonstop0h 00m

C$ 343

SeattleWashington, D.C.

SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl

SEAIAD

Seattle/Tacoma Intl

Sun 27/12

11:03 p.m.-7:04 a.m.

Nonstop5h 01m

Washington, D.C. Dulles Intl

Wed 31/12

12:00 a.m.-9:00 p.m.

Nonstop0h 00m

C$ 357

SeattleWashington, D.C.

SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl

SEAIAD

Seattle/Tacoma Intl

Sat 26/12

3:53 p.m.-11:53 p.m.

Nonstop5h 00m

Washington, D.C. Dulles Intl

Wed 31/12

12:00 a.m.-9:00 p.m.

Nonstop0h 00m

C$ 371

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/9

Showing 1-10 of 24 resultsSorted by cheapest first

Best time to book a flight from Seattle to Dulles Intl

Have a flexible travel schedule? Discover the best time to fly to Dulles Intl from Seattle with our price prediction graph.

SEA-IAD

Estimated round-trip price

Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Seattle to Washington, D.C. Dulles Intl Airport

Prices

Airlines

How far ahead should I book a flight from Seattle to Washington, D.C. Dulles Intl Airport?

Booking 76 days in advance of your planned departure date is, on average, the best time to get cheap flights from Seattle to Washington, D.C. Dulles Intl Airport. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

What is the cheapest month to book a flight from Seattle to Washington, D.C. Dulles Intl Airport?

Currently, February is the cheapest month in which you can book a flight from Seattle to Washington, D.C. Dulles Intl Airport (average of C$ 426). Flying from Seattle to Washington, D.C. Dulles Intl Airport in January is currently the most expensive (average of C$ 920). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from SEA to IAD?

A simple way to save on the total cost of your ticket is to fly from Seattle to Washington, D.C. Dulles Intl Airport in the afternoon. If you’re flexible enough to do this you can expect to save up to 62% on your trip compared to booking a flight in the morning.

How much does it cost to fly round-trip from Seattle to Washington, D.C. Dulles Intl Airport?

Airfare is typical for this route at the moment.

Seattle to Washington, D.C. Dulles Intl Airport flights typically cost between C$ 396 and C$ 776 in October.
The cheapest round-trip price found within the last 5 days was C$ 422 on United Airlines (8 Oct-10 Oct).

Related info for your journey

What airport do you fly from for flights from Seattle to Washington, D.C. Dulles Intl?
If you book a flight to Washington, D.C. Dulles Intl from Seattle, you will be flying from Seattle/Tacoma Intl, which is the city’s only airport. Seattle/Tacoma Intl (SEA) is located 18.4 km from the centre of Seattle. There are 11 flights from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl per day from 0 different airlines.
How long is the flight from Seattle to Washington, D.C. Dulles Intl Airport?
United Airlines and Alaska Airlines can get you from Seattle to Washington, D.C. Dulles Intl Airport in just under 5h 03m. Your travel time can differ by up to 2h 58m. Seattle and Washington, D.C. Dulles Intl Airport are separated by a distance of 3700 km. This flight may include one or multiple stops.
What are the most reliable airlines from Seattle to Washington, D.C. Dulles Intl Airport?
Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Seattle to Washington, D.C. Dulles Intl Airport on time: Qatar Airways (93%), Iberia (91%), Austrian Airlines (90%).
What are the cheapest flights from Seattle to Washington, D.C. Dulles Intl Airport?
While on average a flight from Seattle to Washington, D.C. Dulles Intl Airport is generally C$ 1,103, our data shows the cheapest flight currently is C$ 318. When looking at the most popular route, (Seattle/Tacoma Intl - Washington, D.C. Dulles Intl), you can expect to pay C$ 465 for that flight.
Can I find deals for flights from Seattle to Dulles Intl that include hotel bookings?
Yes. In addition to deals on Seattle to Dulles Intl flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from Seattle to Dulles Intl?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Seattle to Dulles Intl.
Can I find deals for business class flights from Seattle to Dulles Intl?
Yes. Cheapflights offers flight deals from Seattle to Dulles Intl by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.
What is the cheapest month to book a flight from Seattle to Washington, D.C. Dulles Intl Airport?
Currently, February is the cheapest month in which you can book a flight from Seattle to Washington, D.C. Dulles Intl Airport (average of C$ 426). Flying from Seattle to Washington, D.C. Dulles Intl Airport in January is currently the most expensive (average of C$ 920). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Silver Spring

Winchester

Alexandria

Hanover

Oxon Hill

Gaithersburg

Reston

Chantilly

Herndon

Ellicott City

Arlington

Fredericksburg

Ashburn

Rockville

Browse thousands of different options on Cheapflights for your next trip

Alternative routes

Complete your trip

Direct flights to District of Columbia

Dulles Intl flight routes

Flights by cabin class

Other flight options

Other flights from Seattle

Popular flights

Alternative routes for Seattle to Dulles Intl

Seattle to Reagan-National flights

Fly with Cheapflights

How does Cheapflights help users find flights from Seattle to Dulles Intl?

900+ travel sites are searched through when a user searches for a flight using Cheapflights. From the search interface, users can use filters to choose airlines, airports, flight times, cabin classes and more to their preference. Book your flight to Dulles Intl from Seattle today with Cheapflights!

Why should you use Cheapflights to find cheap flight tickets from Seattle to Dulles Intl?

Cheapflights helps you find that perfect flight to Dulles Intl from Seattle by searching from hundreds of airlines and agencies you know and love. We are also free to use, in case you were wondering!

Can Cheapflights find flights from Seattle to Dulles Intl with no change fees?

Cheapflights does show flights with no change fees to all users. To see these options for flights from Seattle to Dulles Intl, users can toggle the no change fees filter when performing a flight search.

Can Cheapflights notify me if prices for flights from Seattle to Dulles Intl become cheaper?

Yes, and it’s super simple to set up. Click the bell icon next to the flight deals above and provide a valid email address to enable Price Alerts. That’s it!

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.

Cheap flights from Seattle to Washington, D.C. Dulles Intl Airport from C$ 261

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 15/10. Fares are subject to change and may not be available on all flights or dates of travel.

Cheap flight deals from Seattle to Dulles Intl

Cheapest flights from Seattle to Dulles IntlExplore the most affordable flight options available from Seattle to Dulles Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 9 September 2026.

Explore the most affordable flight options available from Seattle to Dulles Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 9 September 2026.

Best flights from Seattle to Dulles IntlDiscover carefully curated flight deals from Seattle to Dulles Intl that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated 9 September 2026.

Discover carefully curated flight deals from Seattle to Dulles Intl that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated 9 September 2026.

Direct flights from Seattle to Dulles IntlExplore direct flight options from Seattle to Dulles Intl based on user searches, and compare prices and availability for your desired travel dates. Data last updated 9 September 2026.

Explore direct flight options from Seattle to Dulles Intl based on user searches, and compare prices and availability for your desired travel dates. Data last updated 9 September 2026.

Last-minute flights from Seattle to Dulles IntlDiscover last-minute flight deals from Seattle to Dulles Intl. Data last updated 9 September 2026 and is based on user searches.

Discover last-minute flight deals from Seattle to Dulles Intl. Data last updated 9 September 2026 and is based on user searches.

One-way flights from Seattle to Dulles IntlSearch for one-way flight options from Seattle to Dulles Intl. Find affordable one-way fares based on user searches. Data last updated 9 September 2026.

Search for one-way flight options from Seattle to Dulles Intl. Find affordable one-way fares based on user searches. Data last updated 9 September 2026.

Find flight deals from Seattle to Dulles Intl

Round-trip from

One-way from

Popular in

Cheapest in

Average price

Good round-trip deal

Good one-way deal

Cheapflights Fare Finder

Use the filters below to find and compare flights from Seattle to Washington, D.C. Dulles Intl Airport that are best for you.

Best time to book a flight from Seattle to Dulles Intl

Have a flexible travel schedule? Discover the best time to fly to Dulles Intl from Seattle with our price prediction graph.

Cheapflights Insights

How far ahead should I book a flight from Seattle to Washington, D.C. Dulles Intl Airport?

Booking 76 days in advance of your planned departure date is, on average, the best time to get cheap flights from Seattle to Washington, D.C. Dulles Intl Airport. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

What is the cheapest month to book a flight from Seattle to Washington, D.C. Dulles Intl Airport?

What is the cheapest time of day to fly from SEA to IAD?

A simple way to save on the total cost of your ticket is to fly from Seattle to Washington, D.C. Dulles Intl Airport in the afternoon. If you’re flexible enough to do this you can expect to save up to 62% on your trip compared to booking a flight in the morning.

How much does it cost to fly round-trip from Seattle to Washington, D.C. Dulles Intl Airport?

Airfare is typical for this route at the moment.

Seattle to Washington, D.C. Dulles Intl Airport flights typically cost between C$ 396 and C$ 776 in October.The cheapest round-trip price found within the last 5 days was C$ 422 on United Airlines (8 Oct-10 Oct).

Weekly flight availability from Seattle to Washington, D.C. Dulles Intl Airport

The most flights from SEA to IAD are scheduled on a Tuesday (20 on average). You will have fewer flight options on Sunday, which is when the least amount of flights are scheduled (8 on average).

Related info for your journey

What airport do you fly from for flights from Seattle to Washington, D.C. Dulles Intl?

How long is the flight from Seattle to Washington, D.C. Dulles Intl Airport?

What are the most reliable airlines from Seattle to Washington, D.C. Dulles Intl Airport?

What are the cheapest flights from Seattle to Washington, D.C. Dulles Intl Airport?

Can I find deals for flights from Seattle to Dulles Intl that include hotel bookings?

How can I find direct flights from Seattle to Dulles Intl?

Can I find deals for business class flights from Seattle to Dulles Intl?

What is the cheapest month to book a flight from Seattle to Washington, D.C. Dulles Intl Airport?

Travelling to a place near Washington, D.C. Dulles Intl Airport?

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for Seattle to Dulles Intl

See prices for flight routes from nearby airports that may be better suited for you.

Complete your trip

Complete your trip to Dulles Intl by adding a car rental and/or hotel reservation to your travel itinerary.

Direct flights to District of Columbia

Book a non-stop flight to one of these other cities located in District of Columbia.

Other flights to Dulles Intl

Explore flights to Dulles Intl departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on 9 September 2026.

Search flights from Seattle to Dulles Intl by cabin class

Find flights from Seattle to Dulles Intl, based on your preferred cabin class, be it economy, premium economy, business, or first class.

Seattle and Dulles Intl flights

Browse other Seattle and Dulles Intl flight options. Last updated on 9 September 2026.

Other flights from Seattle

Browse through other flights departing from Seattle. Flights are based on user searches made on Cheapflights and were last updated on 9 September 2026.

Popular flight searches

Check out other popular destinations found by fellow travellers in 2026

Fly with Cheapflights

How does Cheapflights help users find flights from Seattle to Dulles Intl?

Why should you use Cheapflights to find cheap flight tickets from Seattle to Dulles Intl?

Can Cheapflights find flights from Seattle to Dulles Intl with no change fees?

Can Cheapflights notify me if prices for flights from Seattle to Dulles Intl become cheaper?

100% Free

Book with Flexibility

Travel Smart

Cheapest flights from Seattle to Dulles Intl
Explore the most affordable flight options available from Seattle to Dulles Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 9 September 2026.

Best flights from Seattle to Dulles Intl
Discover carefully curated flight deals from Seattle to Dulles Intl that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated 9 September 2026.

Direct flights from Seattle to Dulles Intl
Explore direct flight options from Seattle to Dulles Intl based on user searches, and compare prices and availability for your desired travel dates. Data last updated 9 September 2026.

Last-minute flights from Seattle to Dulles Intl
Discover last-minute flight deals from Seattle to Dulles Intl. Data last updated 9 September 2026 and is based on user searches.

One-way flights from Seattle to Dulles Intl
Search for one-way flight options from Seattle to Dulles Intl. Find affordable one-way fares based on user searches. Data last updated 9 September 2026.

Seattle to Washington, D.C. Dulles Intl Airport flights typically cost between C$ 396 and C$ 776 in October.
The cheapest round-trip price found within the last 5 days was C$ 422 on United Airlines (8 Oct-10 Oct).